Cut rounds from slices of bread using a round cutter 2 1/2 to 3 inches in diameter.
From half of the bread rounds, cut smaller rounds from the centre, making them into rings.
Toast the rounds and rings slightly or leave them untoasted.
Melt butter in a pan and fry onion.
Cook for two minutes.
Add rest of the ingredients.
Place about a tablespoon of the filling on each round and cover with the ring.
Garnish with coriander leaves in the open centre.